饲粮色氨酸水平对扬州鹅蛋白质代谢的影响

Effects of Dietary Tryptophan Level on Protein Metabolism of Yangzhou Goslings

本试验旨在研究饲粮中色氨酸(Trp)水平和饲喂方式对扬州鹅蛋白质代谢的影响。选用270只21日龄的扬州鹅,随机分成6组,每组3个重复,每个重复15只。采用2×3双因子试验设计,饲喂方式为自由采食和90%限制饲喂,饲粮Trp水平分别为0.14%(Ⅰ组)、0.22%(Ⅱ组)和0.30%(Ⅲ组)。试验期42 d。结果表明:1)饲喂方式可显著影响鹅胸肌、腿肌蛋白质沉积量和肝脏粗蛋白质含量(P<0.05);与Ⅰ组相比,Ⅱ组、Ⅲ组胸肌蛋白质沉积量和腿肌粗蛋白质含量显著提高(P<0.05);Trp水平和饲喂方式对肝脏粗蛋白质含量有显著交互作用(P<0.05)。2)限制饲喂Ⅲ组血清Trp/大分子中性氨基酸值显著高于Ⅰ组(P<0.05)。与Ⅰ组相比,Ⅱ组、Ⅲ组血清总蛋白含量显著提高(P<0.05),Ⅲ组血清尿酸含量和Ⅱ组血清皮质醇含量显著降低(P<0.05),Trp水平和饲喂方式对血清生化指标无显著交互作用(P>0.05)。3)Ⅱ组、Ⅲ组腿肌蛋白质相对合成率和蛋白质相对生长率显著高于Ⅰ组(P<0.05)。由此可见,在低Trp水平饲粮中添加Trp可以提高扬州鹅机体蛋白质的沉积。

This study was conducted to investigate the effects of dietary tryptophan level and feeding regimen on protein metabolism of Yangzhou goslings. A total of two hundred and seventy 21-day-old Yangzhou goslings were used in a 2 × 3 double factorial design trial and randomly assigned to 6 groups with 3 replicates in each group and 15 goslings in each replicate. Treatments consisted of two feeding regimens （ad libitum and 90% feed restriction）, and each contained three dietary tryptophan levels （ group Ⅰ 0.14% , group 11 0.22% and group Ⅲ 0.30% ）. The experiment lasted for 42 days. The results showed as follows ： 1 ） feeding regimen had significant effects on protein deposition content （PDC） in breast and thigh and crude protein （CP） content in liver （P 〈 0.05）, the breast PDC and thigh CP content in groups Ⅱ and Ⅲwere significantly increased than those in group Ⅰ （P 〈 0.05 ）, and the interaction between feeding regimen and dietary tryptophan level was significant in the liver CP content （ P 〈 0.05 ）. 2 ） The serum tryptophan/LNAAs （ large neutral amino acids） in restricted feeding group Ⅱwas significantly higher than that in group Ⅰ （ P 〈 0.05 ）. Compared with group Ⅰ , the serum total protein content in groups Ⅱ and Ⅲ was significantly increased （ P 〈 0.05 ）, while the ser- um uric acid content in groupⅢ and serum cortisol content in group Ⅱ were significantly decreased （ P 〈 0.05）. No interaction was found between dietary tryptophan level and feeding regimen in serum biochemical parameters （ P 〈 0.05 ）. 3 ） The protein fractional synthesis rate and fractional growth rate in groupsⅡ and Ⅲ were significantly higher than those in group Ⅰ （ P 〈 0.05）. In conclusion, adding tryptophan in low dietary tryptophan level diet can increase the body protein deposition of Yangzhou goslings.